Conan Mobile Toilet

The case involving a mobile toilet in Detective Conan appears in TV episodes 744 - 745 (overseas split version episodes 797 - 798) titled 'The Suspect is Kyogoku Makoto'.

Basic Case Information

In the case, a physical education teacher drowned in a mobile toilet. However, there was no water at the scene, yet the cause of death was determined to be drowning. This bizarre situation triggered an investigation.

The Criminal's Modus Operandi

The criminal used the principle of gas combustion in a confined space to commit the crime. Specifically, they first blocked the drain outside the toilet so that rainwater would accumulate when it rained. Then, they used a stun gun to knock out the victim and placed them inside the toilet. Next, they placed a large amount of burning kerosene on the shelf above the toilet, closed the toilet door, and sealed the gaps with tape, leaving only a small gap at the bottom. When the kerosene burned, the heated air expanded and escaped through the exhaust vent at the bottom of the toilet. After the kerosene burned out the oxygen and extinguished, the temperature dropped, and the air contracted. Since the drain was blocked, rainwater would backflow into the toilet, ultimately causing the victim to drown.

Controversy Over the Modus Operandi

However, there is some controversy surrounding this modus operandi. Some people question it based on the principle of the 'candle water-sucking' experiment. Candle combustion consumes oxygen, and oxygen only accounts for 21% of the air. According to this proportion, even if a similar backflow phenomenon occurs, it can only reach a maximum of one-fifth, making it difficult to achieve the complete coverage effect shown in the animation. Therefore, this method of killing through thermal expansion and contraction may not be very feasible in actual scientific logic. The plot in the animation may have some exaggeration and artistic embellishment, and there is a certain gap from real-world scientific principles.